Fuel-supply pump



April 8, 1924. 1,489,528

K. J. E. HESSELMAN FUEL SUPPLY BUMP Filed Sept. 26. 1922 Patented Apr. 8, 1924.

PATENT OFFICE;

KNU'I' JONAS ELIAS HESSELMAN, F SALTSJ'O-STORANGEN, SWEDEN.

FUEL-SUPPLY PUMP.

' Application filed September 26, 1922. Serial No. 590,720.

To allwltom it may concern:

Be it known that I, KNUT JONAS ELIAS HESSELMAN, a citizen of the Kingdom of Sweden, residing at Saltsjo-Storangen, 5 Sweden, have invented new and useful Improvements in Fuel-Supply Pumps, of which the following is a Specification.

In the type of fuel supply pumps for internal combustion engines in which the plunger packing does not comprise a stufling box but is realized by using an exceedingly accurate fitting of the plungerin its guideway, it is of the uttermost importance to prevent the plunger from exerting any pres,- sure on the said guide-way due to lateral forces, as, otherwise, wear on the plunger with resulting leakage would easily occur. In order to avoid said inconvenienceit has been proposed to mount the plunger so as Y to permit it to move laterally relatively to its crosshead. In this way, however, the

said inconvenience cannot 'be positively avoided, as friction will, of course, take place in the contact surfaces between the plunger and the-crosshead, the latter having, furthermore, certain, though slight, lateral movements because of the fact that it is impossible to obtain an absolutely ac! curate fitting of the crosshead in its guideobtainnient of the result desired is due to the fact that the said guide-way cannot be made mathematically parallel to the plunger guide-way. This invention has for its object to provide means whereby any lateral force on the plunger is. positively excluded.

-The invention is characterized by the fact that a portion of the plunger situated be-e tween the plunger guide-way and the crosshead of the plunger is'made-elastic so as to be capable of yielding laterally in agreement with the play existing at the crosshead as well as in agreement with inac curacies that might exist in the parallellism of the crosshead relatively to the plunger guide-way.

In the accompanying drawing, alongitudinal section of a pump arrangement accordingto this inventionris shown.

With reference to the drawing, the pump way. A still further obstacle against the whichis, in turn, driven by a cam 3 on the shaft 4. The plunger is mounted to snugly fit in the guide-way 5, and the cross-headis provided with a similar guide-way 6. A portion of the pump plunger is considerably reduced in diameter. relatively to that of the plunger guide-way 5, as shown at 7, said portion having a convex head and being only dimensioned so as to satisfy the requirements as to resistance to lateral fiexure and resistance to compressive stress while being capable of yielding laterally to such an extent as to compensate for the play that might exist at the cross-head, as stated above, as well as to compensate for inac-. curacies that might exist as regards the parallelism between the guide-ways 5 and 6.

Vhat- I claim is v 1. In a fuel pump for internal combustion engines, comprising a pump cylinder, a plunger member ground to fit exactly in said cylinder, a reciprocating cross-head member to drive said plunger, and a rigid guide for, the cross-head, the combination with said ground-in plunger and said cross- -head, of alaterally yielding rod rigidly connected to one member andfhaving a convex lbiead bearing loosely against the other mem- 2. In a fuel pump for internal combus- \tion engines, the combination with a pump cylinder, a plunger-member ground to fit said .cylinder, a reciprocating cross-head 85 member and a rigid guide for the cross-head;

of a laterally yielding rod rigidly connected to one of said members and having a convex head bearing loosely against the other membe and a spring arranged to retract'the plunger; r I

3. In a fuel pump for internal combustion engines, the combination with a pum cylinder, a plunger ground to fit said cy inder, a reciprocating cross-head and a stationary guidev for said cross-head; of a yielding-rod connected to said piston and. having a convex head-bearing. loosely against the. cross=head, and'a coil spring surrounding said rod and operating against said head- 10C to retr'act said piston.

In testimony whereof I have signed my name.

1 Jonas was HESSELMAN. 

